Time varying performance indication system for connected equipment

ABSTRACT

Systems and methods of generating performance index for connected equipment in a building management system are provided. The connected equipment measures monitored variables and generates status codes. The system obtains data points of the monitored variables and the status codes from past N time units, and connected equipment specific parameters. The system performs first performance checks for the connected equipment using the status codes from the past N time units. The system performs second performance checks using the data points of the monitored variables from the past N time units, the connected equipment specific parameters, and a set of predetermined rules. The system determines individual performance check indicators based on the first performance checks and the second performance checks using first weights each determined based on a different timing. The system generates an overall performance index for the connected equipment using the individual performance check indicators and second weights.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. Non-Provisional patentapplication Ser. No. 16/245,122, filed Jan. 10, 2019, which isincorporated herein by reference in its entirety.

BACKGROUND

The present disclosure relates generally to building management systems.The present disclosure relates more particularly to fault detection andgenerating an overall performance index for connected equipment in abuilding management system. A building management system (BMS) is, ingeneral, a system of devices configured to control, monitor, and manageequipment in or around a building or building area. A BMS can include,for example, a HVAC system, a security system, a lighting system, a firealerting system, any other system that is capable of managing buildingfunctions or devices, or any combination thereof.

Systems and devices in a BMS often generate temporal or time-series datathat can be analyzed to determine the performance of the BMS and thevarious components thereof. The data generated by the BMS can includemeasured or calculated values that exhibit statistical characteristicsand provide information about how the corresponding system or process(e.g., a temperature control process, a flow control process, etc.) isperforming in terms of error from its setpoint. These data can beexamined and alert a user to repair the fault before it becomes moresevere when the monitored system or process begins to degrade inperformance.

SUMMARY

One implementation of the present disclosure is a system for generatinga performance index for connected equipment. The system includes theconnected equipment and a time varying performance indication system.The connected equipment can be configured to measure a plurality ofmonitored variables and generate a plurality of status codes. The timevarying performance indication system can be configured to obtain datapoints of the plurality of monitored variables and the plurality ofstatus codes from past N time units, and N is a number. The time varyingperformance indication system can be configured to obtain a plurality ofconnected equipment specific parameters that are parameters specific tothe connected equipment. The time varying performance indication systemcan be configured to perform a plurality of first performance checks forthe connected equipment using the plurality of status codes from thepast N time units. The time varying performance indication system can beconfigured to perform a plurality of second performance checks for theconnected equipment using the data points of the plurality of monitoredvariables from the past N time units, the plurality of connectedequipment specific parameters, and a plurality of predetermined rules.The time varying performance indication system can be configured todetermine a plurality of individual performance check indicators basedon the first performance checks and the second performance checks usinga plurality of first weights each determined based on a differenttiming. The time varying performance indication system can be configuredto generate an overall performance index for the connected equipmentusing the plurality of individual performance check indicators and aplurality of second weights.

In some embodiments, the connected equipment is a chiller.

In some embodiments, the plurality of second performance checks areperformed by applying the data points of the plurality of monitoredvariables from the past N time units and the plurality of connectedequipment specific parameters to the plurality of predetermined rules.

In some embodiments, each of the plurality of second weights isdetermined based on a predetermined degree of severity of a respectivefirst performance check or a respective second performance check.

In some embodiments, the time varying performance indication system canbe configured to determine that a total runtime of the connectedequipment in a past time window, and generate the overall performanceindex only when the total runtime of the connected equipment in the pasttime window satisfies a predetermine threshold.

In some embodiments, the time varying performance indication system canbe configured to cause an adjustment to the connected equipment based onthe overall performance index generated for the connected equipment.

In some embodiments, the time units are days, hours, minutes, seconds,weeks, months, or years.

In some embodiments, the first performance checks are status checks andthe second performance checks are health checks.

Another implementation of the present disclosure is a method forgenerating a performance index for connected equipment. The methodincludes obtaining, by a time varying performance indication systemcomprising a processing circuit and memory, data points of a pluralityof monitored variables and a plurality of status codes from past N timeunits. N is a number. The plurality of monitored variables are measuredby connected equipment, and the plurality of status codes are generatedby the connected equipment. The method includes obtaining, by the timevarying performance indication system, a plurality of connectedequipment specific parameters that are parameters specific to theconnected equipment. The method includes performing, by the time varyingperformance indication system, a plurality of first performance checksfor the connected equipment using the plurality of status codes from thepast N time units. The method includes performing, by the time varyingperformance indication system, a plurality of second performance checksfor the connected equipment using the data points of the plurality ofmonitored variables from the past N time units, the plurality ofconnected equipment specific parameters, and a plurality ofpredetermined rules. The method includes determining, by the timevarying performance indication system, a plurality of individualperformance check indicators based on the first performance checks andthe second performance checks using a plurality of first weights eachdetermined based on a different timing. The method includes generating,by the time varying performance indication system, an overallperformance index for the connected equipment using the plurality ofindividual performance check indicators and a plurality of secondweights.

In some embodiments, the method includes determining that a totalruntime of the connect equipment in a past time window, and generatingthe overall performance index only when the total runtime of the connectequipment in the past time window satisfies a predetermine threshold.

In some embodiments, the method includes causing an adjustment to theconnect equipment based on the overall performance index generated forthe connected equipment.

Another implementation of the present disclosure is a non-transitorycomputer-readable medium. The non-transitory computer-readable mediumstores computer-executable instructions that when executed by at leastone processor, causing the at least one processor to perform operationsfor generating a performance index for connected equipment. Theoperations include obtaining data points of a plurality of monitoredvariables and a plurality of status codes from past N time units. N is anumber. The plurality of monitored variables are measured by connectedequipment, and the plurality of status codes are generated by theconnected equipment. The operations include obtaining a plurality ofconnected equipment specific parameters that are parameters specific tothe connected equipment. The operations include performing a pluralityof first performance checks for the connected equipment using theplurality of status codes from the past N time units. The operationsinclude performing a plurality of second performance checks for theconnected equipment using the data points of the plurality of monitoredvariables from the past N time units, the plurality of connectedequipment specific parameters, and a plurality of predetermined rules.The operations include determining a plurality of individual performancecheck indicators based on the first performance checks and the secondperformance checks using a plurality of first weights each determinedbased on a different timing. The operations include generating anoverall performance index for the connected equipment using theplurality of individual performance check indicators and a plurality ofsecond weights.

In some embodiments, the operations include determining that a totalruntime of the connect equipment in a past time window, and generatingthe overall performance index only when the total runtime of the connectequipment in the past time window satisfies a predetermine threshold.

In some embodiments, the operations include causing an adjustment to theconnect equipment based on the overall performance index generated forthe connected equipment.

Those skilled in the art will appreciate that the summary isillustrative only and is not intended to be in any way limiting. Otheraspects, inventive features, and advantages of the devices and/orprocesses described herein, as defined solely by the claims, will becomeapparent in the detailed description set forth herein and taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a drawing of a building equipped with a HVAC system, accordingto some embodiments.

FIG. 2 is a schematic diagram of a waterside system which can be used inconjunction with the building of FIG. 1, according to some embodiments.

FIG. 3 is a schematic diagram of an airside system which can be used inconjunction with the building of FIG. 1, according to some embodiments.

FIG. 4 is a block diagram of a building management system (BMS) whichcan be used to monitor and control the building of FIG. 1, according tosome embodiments.

FIG. 5 is a block diagram of another BMS which can be used to monitorand control the building of FIG. 1 and includes a time varyingperformance indication system, according to some embodiments.

FIG. 6 is a block diagram of another BMS including the time varyingperformance indication system for generating a performance index forconnected equipment, according to some embodiments.

FIG. 7 is a schematic diagram of a chiller, which is an example of atype of connected equipment which can report monitored variables andstatus information to the time varying performance indication system,according to some embodiments.

FIG. 8 is a block diagram of a time varying performance indicationsystem of generating a performance index for connected equipment,according to some embodiments.

FIG. 9 is a high level flow diagram illustrating a process of generatinga performance index for connected equipment, according to someembodiments.

FIG. 10 is a flow diagram illustrating a process of generating aperformance index for connected equipment, according to someembodiments.

FIG. 11 is another flow diagram illustrating a process of generating aperformance index for connected equipment, according to someembodiments.

FIG. 12 is another flow diagram illustrating a process of generating aperformance index for connected equipment, according to someembodiments.

FIG. 13 is a graph illustrating the exponential decay function with atau value of two, according to some embodiments.

FIG. 14 is an example scenario of performance checks for generating anoverall performance index, according to some embodiments.

FIG. 15 is an example user interface illustrating an example of thecalculated performance index over time, according to some embodiments.

FIG. 16 is another flow diagram illustrating a process of generating aperformance index for connected equipment, according to someembodiments.

DETAILED DESCRIPTION

Following below are more detailed descriptions of various conceptsrelated to, and implementations of systems, methods, and apparatuses forgenerating time varying performance indications for connected equipmentin a building management system. Before turning to the more detaileddescriptions and figures, which illustrate the exemplary embodiments indetail, it should be understood that the application is not limited tothe details or methodology set forth in the descriptions or illustratedin the figures. It should also be understood that the terminology is forthe purpose of description only and should not be regarded as limitingin any way.

Building HVAC Systems and Building Management Systems

Referring now to FIGS. 1-5, several building management systems (BMS)and HVAC systems in which the systems and methods of the presentdisclosure can be implemented are shown, according to some embodiments.In brief overview, FIG. 1 shows a building 10 equipped with a HVACsystem 100. FIG. 2 is a block diagram of a waterside system 200 whichcan be used to serve building 10. FIG. 3 is a block diagram of anairside system 300 which can be used to serve building 10. FIG. 4 is ablock diagram of a BMS which can be used to monitor and control building10. FIG. 5 is a block diagram of another BMS which can be used tomonitor and control building 10.

Building 10 and HVAC System 100

Referring particularly to FIG. 1, a perspective view of building 10 isshown. Building 10 is served by a BMS. A BMS is, in general, a system ofdevices configured to control, monitor, and manage equipment in oraround a building or building area. A BMS can include, for example, aHVAC system, a security system, a lighting system, a fire alertingsystem, any other system that is capable of managing building functionsor devices, or any combination thereof.

The BMS that serves building 10 includes an HVAC system 100. HVAC system100 can include a plurality of HVAC devices (e.g., heaters, chillers,air handling units, pumps, fans, thermal energy storage, etc.)configured to provide heating, cooling, ventilation, or other servicesfor building 10. For example, HVAC system 100 is shown to include awaterside system 120 and an airside system 130. Waterside system 120 mayprovide a heated or chilled fluid to an air handling unit of airsidesystem 130. Airside system 130 may use the heated or chilled fluid toheat or cool an airflow provided to building 10. An exemplary watersidesystem and airside system which can be used in HVAC system 100 aredescribed in greater detail with reference to FIGS. 2 and 3.

HVAC system 100 is shown to include a chiller 102, a boiler 104, and arooftop air handling unit (AHU) 106. Waterside system 120 may use boiler104 and chiller 102 to heat or cool a working fluid (e.g., water,glycol, etc.) and may circulate the working fluid to AHU 106. In variousembodiments, the HVAC devices of waterside system 120 can be located inor around building 10 (as shown in FIG. 1) or at an offsite locationsuch as a central plant (e.g., a chiller plant, a steam plant, a heatplant, etc.). The working fluid can be heated in boiler 104 or cooled inchiller 102, depending on whether heating or cooling is required inbuilding 10. Boiler 104 may add heat to the circulated fluid, forexample, by burning a combustible material (e.g., natural gas) or usingan electric heating element. Chiller 102 may place the circulated fluidin a heat exchange relationship with another fluid (e.g., a refrigerant)in a heat exchanger (e.g., an evaporator) to absorb heat from thecirculated fluid. The working fluid from chiller 102 and/or boiler 104can be transported to AHU 106 via piping 108.

AHU 106 may place the working fluid in a heat exchange relationship withan airflow passing through AHU 106 (e.g., via one or more stages ofcooling coils and/or heating coils). The airflow can be, for example,outside air, return air from within building 10, or a combination ofboth. AHU 106 may transfer heat between the airflow and the workingfluid to provide heating or cooling for the airflow. For example, AHU106 can include one or more fans or blowers configured to pass theairflow over or through a heat exchanger containing the working fluid.The working fluid may then return to chiller 102 or boiler 104 viapiping 110.

Airside system 130 may deliver the airflow supplied by AHU 106 (i.e.,the supply airflow) to building 10 via air supply ducts 112 and mayprovide return air from building 10 to AHU 106 via air return ducts 114.In some embodiments, airside system 130 includes multiple variable airvolume (VAV) units 116. For example, airside system 130 is shown toinclude a separate VAV unit 116 on each floor or zone of building 10.VAV units 116 can include dampers or other flow control elements thatcan be operated to control an amount of the supply airflow provided toindividual zones of building 10. In other embodiments, airside system130 delivers the supply airflow into one or more zones of building 10(e.g., via supply ducts 112) without using intermediate VAV units 116 orother flow control elements. AHU 106 can include various sensors (e.g.,temperature sensors, pressure sensors, etc.) configured to measureattributes of the supply airflow. AHU 106 may receive input from sensorslocated within AHU 106 and/or within the building zone and may adjustthe flow rate, temperature, or other attributes of the supply airflowthrough AHU 106 to achieve setpoint conditions for the building zone.

Waterside System 200

Referring now to FIG. 2, a block diagram of a waterside system 200 isshown, according to some embodiments. In various embodiments, watersidesystem 200 may supplement or replace waterside system 120 in HVAC system100 or can be implemented separate from HVAC system 100. Whenimplemented in HVAC system 100, waterside system 200 can include asubset of the HVAC devices in HVAC system 100 (e.g., boiler 104, chiller102, pumps, valves, etc.) and may operate to supply a heated or chilledfluid to AHU 106. The HVAC devices of waterside system 200 can belocated within building 10 (e.g., as components of waterside system 120)or at an offsite location such as a central plant.

In FIG. 2, waterside system 200 is shown as a central plant having aplurality of subplants 202-212. Subplants 202-212 are shown to include aheater subplant 202, a heat recovery chiller subplant 204, a chillersubplant 206, a cooling tower subplant 208, a hot thermal energy storage(TES) subplant 210, and a cold thermal energy storage (TES) subplant212. Subplants 202-212 consume resources (e.g., water, natural gas,electricity, etc.) from utilities to serve thermal energy loads (e.g.,hot water, cold water, heating, cooling, etc.) of a building or campus.For example, heater subplant 202 can be configured to heat water in ahot water loop 214 that circulates the hot water between heater subplant202 and building 10. Chiller subplant 206 can be configured to chillwater in a cold water loop 216 that circulates the cold water betweenchiller subplant 206 building 10. Heat recovery chiller subplant 204 canbe configured to transfer heat from cold water loop 216 to hot waterloop 214 to provide additional heating for the hot water and additionalcooling for the cold water. Condenser water loop 218 may absorb heatfrom the cold water in chiller subplant 206 and reject the absorbed heatin cooling tower subplant 208 or transfer the absorbed heat to hot waterloop 214. Hot TES subplant 210 and cold TES subplant 212 may store hotand cold thermal energy, respectively, for subsequent use.

Hot water loop 214 and cold water loop 216 may deliver the heated and/orchilled water to air handlers located on the rooftop of building 10(e.g., AHU 106) or to individual floors or zones of building 10 (e.g.,VAV units 116). The air handlers push air past heat exchangers (e.g.,heating coils or cooling coils) through which the water flows to provideheating or cooling for the air. The heated or cooled air can bedelivered to individual zones of building 10 to serve thermal energyloads of building 10. The water then returns to subplants 202-212 toreceive further heating or cooling.

Although subplants 202-212 are shown and described as heating andcooling water for circulation to a building, it is understood that anyother type of working fluid (e.g., glycol, CO2, etc.) can be used inplace of or in addition to water to serve thermal energy loads. In otherembodiments, subplants 202-212 may provide heating and/or coolingdirectly to the building or campus without requiring an intermediateheat transfer fluid. These and other variations to waterside system 200are within the teachings of the present invention.

Each of subplants 202-212 can include a variety of equipment configuredto facilitate the functions of the subplant. For example, heatersubplant 202 is shown to include a plurality of heating elements 220(e.g., boilers, electric heaters, etc.) configured to add heat to thehot water in hot water loop 214. Heater subplant 202 is also shown toinclude several pumps 222 and 224 configured to circulate the hot waterin hot water loop 214 and to control the flow rate of the hot waterthrough individual heating elements 220. Chiller subplant 206 is shownto include a plurality of chillers 232 configured to remove heat fromthe cold water in cold water loop 216. Chiller subplant 206 is alsoshown to include several pumps 234 and 236 configured to circulate thecold water in cold water loop 216 and to control the flow rate of thecold water through individual chillers 232.

Heat recovery chiller subplant 204 is shown to include a plurality ofheat recovery heat exchangers 226 (e.g., refrigeration circuits)configured to transfer heat from cold water loop 216 to hot water loop214. Heat recovery chiller subplant 204 is also shown to include severalpumps 228 and 230 configured to circulate the hot water and/or coldwater through heat recovery heat exchangers 226 and to control the flowrate of the water through individual heat recovery heat exchangers 226.Cooling tower subplant 208 is shown to include a plurality of coolingtowers 238 configured to remove heat from the condenser water incondenser water loop 218. Cooling tower subplant 208 is also shown toinclude several pumps 240 configured to circulate the condenser water incondenser water loop 218 and to control the flow rate of the condenserwater through individual cooling towers 238.

Hot TES subplant 210 is shown to include a hot TES tank 242 configuredto store the hot water for later use. Hot TES subplant 210 may alsoinclude one or more pumps or valves configured to control the flow rateof the hot water into or out of hot TES tank 242. Cold TES subplant 212is shown to include cold TES tanks 244 configured to store the coldwater for later use. Cold TES subplant 212 may also include one or morepumps or valves configured to control the flow rate of the cold waterinto or out of cold TES tanks 244.

In some embodiments, one or more of the pumps in waterside system 200(e.g., pumps 222, 224, 228, 230, 234, 236, and/or 240) or pipelines inwaterside system 200 include an isolation valve associated therewith.Isolation valves can be integrated with the pumps or positioned upstreamor downstream of the pumps to control the fluid flows in watersidesystem 200. In various embodiments, waterside system 200 can includemore, fewer, or different types of devices and/or subplants based on theparticular configuration of waterside system 200 and the types of loadsserved by waterside system 200.

Airside System 300

Referring now to FIG. 3, a block diagram of an airside system 300 isshown, according to some embodiments. In various embodiments, airsidesystem 300 may supplement or replace airside system 130 in HVAC system100 or can be implemented separate from HVAC system 100. Whenimplemented in HVAC system 100, airside system 300 can include a subsetof the HVAC devices in HVAC system 100 (e.g., AHU 106, VAV units 116,ducts 112-114, fans, dampers, etc.) and can be located in or aroundbuilding 10. Airside system 300 may operate to heat or cool an airflowprovided to building 10 using a heated or chilled fluid provided bywaterside system 200.

In FIG. 3, airside system 300 is shown to include an economizer-type airhandling unit (AHU) 302. Economizer-type AHUs vary the amount of outsideair and return air used by the air handling unit for heating or cooling.For example, AHU 302 may receive return air 304 from building zone 306via return air duct 308 and may deliver supply air 310 to building zone306 via supply air duct 312. In some embodiments, AHU 302 is a rooftopunit located on the roof of building 10 (e.g., AHU 106 as shown inFIG. 1) or otherwise positioned to receive both return air 304 andoutside air 314. AHU 302 can be configured to operate exhaust air damper316, mixing damper 318, and outside air damper 320 to control an amountof outside air 314 and return air 304 that combine to form supply air310. Any return air 304 that does not pass through mixing damper 318 canbe exhausted from AHU 302 through exhaust damper 316 as exhaust air 322.

Each of dampers 316-320 can be operated by an actuator. For example,exhaust air damper 316 can be operated by actuator 324, mixing damper318 can be operated by actuator 326, and outside air damper 320 can beoperated by actuator 328. Actuators 324-328 may communicate with an AHUcontroller 330 via a communications link 332. Actuators 324-328 mayreceive control signals from AHU controller 330 and may provide feedbacksignals to AHU controller 330. Feedback signals can include, forexample, an indication of a current actuator or damper position, anamount of torque or force exerted by the actuator, diagnosticinformation (e.g., results of diagnostic tests performed by actuators324-328), status information, commissioning information, configurationsettings, calibration data, and/or other types of information or datathat can be collected, stored, or used by actuators 324-328. AHUcontroller 330 can be an economizer controller configured to use one ormore control algorithms (e.g., state-based algorithms, extremum seekingcontrol (ESC) algorithms, proportional-integral (PI) control algorithms,proportional-integral-derivative (PID) control algorithms, modelpredictive control (MPC) algorithms, feedback control algorithms, etc.)to control actuators 324-328.

Still referring to FIG. 3, AHU 302 is shown to include a cooling coil334, a heating coil 336, and a fan 338 positioned within supply air duct312. Fan 338 can be configured to force supply air 310 through coolingcoil 334 and/or heating coil 336 and provide supply air 310 to buildingzone 306. AHU controller 330 may communicate with fan 338 viacommunications link 340 to control a flow rate of supply air 310. Insome embodiments, AHU controller 330 controls an amount of heating orcooling applied to supply air 310 by modulating a speed of fan 338.

Cooling coil 334 may receive a chilled fluid from waterside system 200(e.g., from cold water loop 216) via piping 342 and may return thechilled fluid to waterside system 200 via piping 344. Valve 346 can bepositioned along piping 342 or piping 344 to control a flow rate of thechilled fluid through cooling coil 334. In some embodiments, coolingcoil 334 includes multiple stages of cooling coils that can beindependently activated and deactivated (e.g., by AHU controller 330, byBMS controller 366, etc.) to modulate an amount of cooling applied tosupply air 310.

Heating coil 336 may receive a heated fluid from waterside system 200(e.g., from hot water loop 214) via piping 348 and may return the heatedfluid to waterside system 200 via piping 350. Valve 352 can bepositioned along piping 348 or piping 350 to control a flow rate of theheated fluid through heating coil 336. In some embodiments, heating coil336 includes multiple stages of heating coils that can be independentlyactivated and deactivated (e.g., by AHU controller 330, by BMScontroller 366, etc.) to modulate an amount of heating applied to supplyair 310.

Each of valves 346 and 352 can be controlled by an actuator. Forexample, valve 346 can be controlled by actuator 354 and valve 352 canbe controlled by actuator 356. Actuators 354-356 may communicate withAHU controller 330 via communications links 358-360. Actuators 354-356may receive control signals from AHU controller 330 and may providefeedback signals to controller 330. In some embodiments, AHU controller330 receives a measurement of the supply air temperature from atemperature sensor 362 positioned in supply air duct 312 (e.g.,downstream of cooling coil 334 and/or heating coil 336). AHU controller330 may also receive a measurement of the temperature of building zone306 from a temperature sensor 364 located in building zone 306.

In some embodiments, AHU controller 330 operates valves 346 and 352 viaactuators 354-356 to modulate an amount of heating or cooling providedto supply air 310 (e.g., to achieve a setpoint temperature for supplyair 310 or to maintain the temperature of supply air 310 within asetpoint temperature range). The positions of valves 346 and 352 affectthe amount of heating or cooling provided to supply air 310 by coolingcoil 334 or heating coil 336 and may correlate with the amount of energyconsumed to achieve a desired supply air temperature. AHU 330 maycontrol the temperature of supply air 310 and/or building zone 306 byactivating or deactivating coils 334-336, adjusting a speed of fan 338,or a combination of both.

Still referring to FIG. 3, airside system 300 is shown to include abuilding management system (BMS) controller 366 and a client device 368.BMS controller 366 can include one or more computer systems (e.g.,servers, supervisory controllers, subsystem controllers, etc.) thatserve as system level controllers, application or data servers, headnodes, or master controllers for airside system 300, waterside system200, HVAC system 100, and/or other controllable systems that servebuilding 10. BMS controller 366 may communicate with multiple downstreambuilding systems or subsystems (e.g., HVAC system 100, a securitysystem, a lighting system, waterside system 200, etc.) via acommunications link 370 according to like or disparate protocols (e.g.,LON, BACnet, etc.). In various embodiments, AHU controller 330 and BMScontroller 366 can be separate (as shown in FIG. 3) or integrated. In anintegrated implementation, AHU controller 330 can be a software moduleconfigured for execution by a processor of BMS controller 366.

In some embodiments, AHU controller 330 receives information from BMScontroller 366 (e.g., commands, setpoints, operating boundaries, etc.)and provides information to BMS controller 366 (e.g., temperaturemeasurements, valve or actuator positions, operating statuses,diagnostics, etc.). For example, AHU controller 330 may provide BMScontroller 366 with temperature measurements from temperature sensors362-364, equipment on/off states, equipment operating capacities, and/orany other information that can be used by BMS controller 366 to monitoror control a variable state or condition within building zone 306.

Client device 368 can include one or more human-machine interfaces orclient interfaces (e.g., graphical user interfaces, reportinginterfaces, text-based computer interfaces, client-facing web services,web servers that provide pages to web clients, etc.) for controlling,viewing, or otherwise interacting with HVAC system 100, its subsystems,and/or devices. Client device 368 can be a computer workstation, aclient terminal, a remote or local interface, or any other type of userinterface device. Client device 368 can be a stationary terminal or amobile device. For example, client device 368 can be a desktop computer,a computer server with a user interface, a laptop computer, a tablet, asmartphone, a PDA, or any other type of mobile or non-mobile device.Client device 368 may communicate with BMS controller 366 and/or AHUcontroller 330 via communications link 372.

Building Management System 400

Referring now to FIG. 4, a block diagram of a building management system(BMS) 400 is shown, according to some embodiments. BMS 400 can beimplemented in building 10 to automatically monitor and control variousbuilding functions. BMS 400 is shown to include BMS controller 366 and aplurality of building subsystems 428. Building subsystems 428 are shownto include a building electrical subsystem 434, an informationcommunication technology (ICT) subsystem 436, a security subsystem 438,a HVAC subsystem 440, a lighting subsystem 442, a lift/escalatorssubsystem 432, and a fire safety subsystem 430. In various embodiments,building subsystems 428 can include fewer, additional, or alternativesubsystems. For example, building subsystems 428 may also oralternatively include a refrigeration subsystem, an advertising orsignage subsystem, a cooking subsystem, a vending subsystem, a printeror copy service subsystem, or any other type of building subsystem thatuses controllable equipment and/or sensors to monitor or controlbuilding 10. In some embodiments, building subsystems 428 includewaterside system 200 and/or airside system 300, as described withreference to FIGS. 2 and 3.

Each of building subsystems 428 can include any number of devices,controllers, and connections for completing its individual functions andcontrol activities. HVAC subsystem 440 can include many of the samecomponents as HVAC system 100, as described with reference to FIGS. 1-3.For example, HVAC subsystem 440 can include a chiller, a boiler, anynumber of air handling units, economizers, field controllers,supervisory controllers, actuators, temperature sensors, thermostats,and other devices for controlling the temperature, humidity, airflow, orother variable conditions within building 10. Lighting subsystem 442 caninclude any number of light fixtures, ballasts, lighting sensors,dimmers, and/or other devices configured to controllably adjust theamount of light provided to a building space. Security subsystem 438 caninclude occupancy sensors, video surveillance cameras, digital videorecorders, video processing servers, intrusion detection devices, accesscontrol devices and servers, and/or other security-related devices.

Still referring to FIG. 4, BMS controller 366 is shown to include acommunications interface 407 and a BMS interface 409. Communicationsinterface 407 may facilitate communications between BMS controller 366and external applications (e.g., monitoring and reporting applications422, enterprise control applications 426, remote systems andapplications 444, applications residing on client devices 448, etc.) forallowing user control, monitoring, and adjustment to BMS controller 366and/or subsystems 428. Communications interface 407 may also facilitatecommunications between BMS controller 366 and client devices 448. BMSinterface 409 may facilitate communications between BMS controller 366and building subsystems 428 (e.g., HVAC, lighting security, lifts, powerdistribution, business, etc.).

Communications interfaces 407 and/or BMS interface 409 can be or includewired or wireless communications interfaces (e.g., jacks, antennas,transmitters, receivers, transceivers, wire terminals, etc.) forconducting data communications with building subsystems 428 or otherexternal systems or devices. In various embodiments, communications viacommunications interfaces 407 and/or BMS interface 409 can be direct(e.g., local wired or wireless communications) or via a communicationsnetwork 446 (e.g., a WAN, the Internet, a cellular network, etc.). Forexample, communications interfaces 407 and/or BMS interface 409 caninclude an Ethernet card and port for sending and receiving data via anEthernet-based communications link or network. In another example,communications interfaces 407 and/or BMS interface 409 can include aWi-Fi transceiver for communicating via a wireless communicationsnetwork. In another example, one or both of communications interfaces407 and BMS interface 409 can include cellular or mobile phonecommunications transceivers. In one embodiment, communications interface407 is a power line communications interface and BMS interface 409 is anEthernet interface. In other embodiments, both communications interface407 and BMS interface 409 are Ethernet interfaces or are the sameEthernet interface.

Still referring to FIG. 4, BMS controller 366 is shown to include aprocessing circuit 404 including a processor 406 and memory 408.Processing circuit 404 can be communicably connected to BMS interface409 and/or communications interface 407 such that processing circuit 404and the various components thereof can send and receive data viacommunications interfaces 407 and/or BMS interface 409. Processor 406can be implemented as a general purpose processor, an applicationspecific integrated circuit (ASIC), one or more field programmable gatearrays (FPGAs), a group of processing components, or other suitableelectronic processing components.

Memory 408 (e.g., memory, memory unit, storage device, etc.) can includeone or more devices (e.g., RAM, ROM, Flash memory, hard disk storage,etc.) for storing data and/or computer code for completing orfacilitating the various processes, layers and modules described in thepresent application. Memory 408 can be or include volatile memory ornon-volatile memory. Memory 408 can include database components, objectcode components, script components, or any other type of informationstructure for supporting the various activities and informationstructures described in the present application. According to someembodiments, memory 408 is communicably connected to processor 406 viaprocessing circuit 404 and includes computer code for executing (e.g.,by processing circuit 404 and/or processor 406) one or more processesdescribed herein.

In some embodiments, BMS controller 366 is implemented within a singlecomputer (e.g., one server, one housing, etc.). In various otherembodiments BMS controller 366 can be distributed across multipleservers or computers (e.g., that can exist in distributed locations).Further, while FIG. 4 shows applications 422 and 426 as existing outsideof BMS controller 366, in some embodiments, applications 422 and 426 canbe hosted within BMS controller 366 (e.g., within memory 408).

Still referring to FIG. 4, memory 408 is shown to include an enterpriseintegration layer 410, an automated measurement and validation (AM&V)layer 412, a demand response (DR) layer 414, a fault detection anddiagnostics (FDD) layer 416, an integrated control layer 418, and abuilding subsystem integration later 420. Layers 410-420 can beconfigured to receive inputs from building subsystems 428 and other datasources, determine optimal control actions for building subsystems 428based on the inputs, generate control signals based on the optimalcontrol actions, and provide the generated control signals to buildingsubsystems 428. The following paragraphs describe some of the generalfunctions performed by each of layers 410-420 in BMS 400.

Enterprise integration layer 410 can be configured to serve clients orlocal applications with information and services to support a variety ofenterprise-level applications. For example, enterprise controlapplications 426 can be configured to provide subsystem-spanning controlto a graphical user interface (GUI) or to any number of enterprise-levelbusiness applications (e.g., accounting systems, user identificationsystems, etc.). Enterprise control applications 426 may also oralternatively be configured to provide configuration GUIs forconfiguring BMS controller 366. In yet other embodiments, enterprisecontrol applications 426 can work with layers 410-420 to optimizebuilding performance (e.g., efficiency, energy use, comfort, or safety)based on inputs received at communications interface 407 and/or BMSinterface 409.

Building subsystem integration layer 420 can be configured to managecommunications between BMS controller 366 and building subsystems 428.For example, building subsystem integration layer 420 may receive sensordata and input signals from building subsystems 428 and provide outputdata and control signals to building subsystems 428. Building subsystemintegration layer 420 may also be configured to manage communicationsbetween building subsystems 428. Building subsystem integration layer420 translate communications (e.g., sensor data, input signals, outputsignals, etc.) across a plurality of multi-vendor/multi-protocolsystems.

Demand response layer 414 can be configured to optimize resource usage(e.g., electricity use, natural gas use, water use, etc.) and/or themonetary cost of such resource usage in response to satisfy the demandof building 10. The optimization can be based on time-of-use prices,curtailment signals, energy availability, or other data received fromutility providers, distributed energy generation systems 424, fromenergy storage 427 (e.g., hot TES 242, cold TES 244, etc.), or fromother sources. Demand response layer 414 may receive inputs from otherlayers of BMS controller 366 (e.g., building subsystem integration layer420, integrated control layer 418, etc.). The inputs received from otherlayers can include environmental or sensor inputs (e.g., internal tobuilding 10, external to building 10, etc.) such as temperature, carbondioxide levels, relative humidity levels, air quality sensor outputs,occupancy sensor outputs, room schedules, weather conditions, and thelike. The inputs may also include inputs such as electrical use (e.g.,expressed in kWh), thermal load measurements, pricing information,projected pricing, smoothed pricing, curtailment signals from utilities,and the like.

According to some embodiments, demand response layer 414 includescontrol logic for responding to the data and signals it receives. Theseresponses can include communicating with the control algorithms inintegrated control layer 418, changing control strategies, changingsetpoints, or activating/deactivating building equipment or subsystemsin a controlled manner. Demand response layer 414 may also includecontrol logic configured to determine when to utilize stored energy. Forexample, demand response layer 414 may determine to begin using energyfrom energy storage 427 just prior to the beginning of a peak use hour.

In some embodiments, demand response layer 414 includes a control moduleconfigured to actively initiate control actions (e.g., automaticallychanging setpoints, etc.) which minimize energy costs based on one ormore inputs representative of or based on demand (e.g., price, acurtailment signal, a demand level, etc.). In some embodiments, demandresponse layer 414 uses equipment models to determine an optimal set ofcontrol actions. The equipment models can include, for example,thermodynamic models describing the inputs, outputs, and/or functionsperformed by various sets of building equipment. Equipment models mayrepresent collections of building equipment (e.g., subplants, chillerarrays, etc.) or individual devices (e.g., individual chillers, heaters,pumps, etc.).

Demand response layer 414 may further include or draw upon one or moredemand response policy definitions (e.g., databases, XML files, etc.).The policy definitions can be edited or adjusted by a user (e.g., via agraphical user interface, etc.) so that the control actions initiated inresponse to demand inputs can be tailored for the user's application,desired comfort level, particular building equipment, and/or based onother concerns. For example, the demand response policy definitions canspecify which equipment can be turned on or off in response toparticular demand inputs, how long a system or piece of equipment shouldbe turned off, what setpoints can be changed, what the allowable setpoint adjustment range is, how long to hold a high demand setpointbefore returning to a normally scheduled setpoint, how close to approachcapacity limits, which equipment modes to utilize, the energy transferrates (e.g., the maximum rate, an alarm rate, other rate boundaryinformation, etc.) into and out of energy storage devices (e.g., thermalstorage tanks, battery banks, etc.), and/or when to dispatch on-sitegeneration of energy (e.g., via fuel cells, a motor generator set,etc.).

Integrated control layer 418 can be configured to use the data input oroutput of building subsystem integration layer 420 and/or demandresponse later 414 to make control decisions. Due to the subsystemintegration provided by building subsystem integration layer 420,integrated control layer 418 can integrate control activities of thesubsystems 428 such that the subsystems 428 behave as a singleintegrated supersystem. In some embodiments, integrated control layer418 includes control logic that uses inputs and outputs from a pluralityof building subsystems to provide greater comfort and energy savingsrelative to the comfort and energy savings that separate subsystemscould provide alone. For example, integrated control layer 418 can beconfigured to use an input from a first subsystem to make anenergy-saving control decision for a second subsystem. Results of thesedecisions can be communicated back to building subsystem integrationlayer 420.

Integrated control layer 418 is shown to be logically below demandresponse layer 414. Integrated control layer 418 can be configured toenhance the effectiveness of demand response layer 414 by enablingbuilding subsystems 428 and their respective control loops to becontrolled in coordination with demand response layer 414. Thisconfiguration may advantageously reduce disruptive demand responsebehavior relative to conventional systems. For example, integratedcontrol layer 418 can be configured to assure that a demandresponse-driven upward adjustment to the setpoint for chilled watertemperature (or another component that directly or indirectly affectstemperature) does not result in an increase in fan energy (or otherenergy used to cool a space) that would result in greater total buildingenergy use than was saved at the chiller.

Integrated control layer 418 can be configured to provide feedback todemand response layer 414 so that demand response layer 414 checks thatconstraints (e.g., temperature, lighting levels, etc.) are properlymaintained even while demanded load shedding is in progress. Theconstraints may also include setpoint or sensed boundaries relating tosafety, equipment operating limits and performance, comfort, fire codes,electrical codes, energy codes, and the like. Integrated control layer418 is also logically below fault detection and diagnostics layer 416and automated measurement and validation layer 412. Integrated controllayer 418 can be configured to provide calculated inputs (e.g.,aggregations) to these higher levels based on outputs from more than onebuilding subsystem.

Automated measurement and validation (AM&V) layer 412 can be configuredto verify that control strategies commanded by integrated control layer418 or demand response layer 414 are working properly (e.g., using dataaggregated by AM&V layer 412, integrated control layer 418, buildingsubsystem integration layer 420, FDD layer 416, or otherwise). Thecalculations made by AM&V layer 412 can be based on building systemenergy models and/or equipment models for individual BMS devices orsubsystems. For example, AM&V layer 412 may compare a model-predictedoutput with an actual output from building subsystems 428 to determinean accuracy of the model.

Fault detection and diagnostics (FDD) layer 416 can be configured toprovide on-going fault detection for building subsystems 428, buildingsubsystem devices (i.e., building equipment), and control algorithmsused by demand response layer 414 and integrated control layer 418. FDDlayer 416 may receive data inputs from integrated control layer 418,directly from one or more building subsystems or devices, and/or fromanother data source. FDD layer 416 may automatically diagnose andrespond to detected faults. The responses to detected or diagnosedfaults can include providing an alert message to a user, a maintenancescheduling system, or a control algorithm configured to attempt torepair the fault or to work-around the fault.

FDD layer 416 can be configured to output a specific identification ofthe faulty component or cause of the fault (e.g., loose damper linkage,etc.) using detailed subsystem inputs available at building subsystemintegration layer 420. In other exemplary embodiments, FDD layer 416 isconfigured to provide “fault” events to integrated control layer 418which executes control strategies and policies in response to thereceived fault events. According to some embodiments, FDD layer 416 (ora policy executed by an integrated control engine or business rulesengine) may shut-down systems or direct control activities around faultydevices or systems to reduce energy waste, extend equipment life, orassure proper control response.

FDD layer 416 can be configured to store or access a variety ofdifferent system data stores (or data points for live data). FDD layer416 may use some content of the data stores to identify faults at theequipment level (e.g., specific chiller, specific AHU, specific terminalunit, etc.) and other content to identify faults at component orsubsystem levels. For example, building subsystems 428 may generatetemporal (i.e., time-series) data indicating the performance of BMS 400and the various components thereof. The data generated by buildingsubsystems 428 can include measured or calculated values that exhibitstatistical characteristics and provide information about how thecorresponding system or process (e.g., a temperature control process, aflow control process, etc.) is performing in terms of error from itssetpoint. These processes can be examined by FDD layer 416 to exposewhen the system begins to degrade in performance and alert a user torepair the fault before it becomes more severe.

Building Management System 500

Referring now to FIG. 5, a block diagram of another building managementsystem (BMS) 500 is shown, according to some embodiments. BMS 500 can beused to monitor and control the devices of HVAC system 100, watersidesystem 200, airside system 300, building subsystems 428, as well asother types of BMS devices (e.g., lighting equipment, securityequipment, etc.) and/or HVAC equipment. In some embodiments, thebuilding management system includes a time varying performanceindication system.

BMS 500 provides a system architecture that facilitates automaticequipment discovery and equipment model distribution. Equipmentdiscovery can occur on multiple levels of BMS 500 across multipledifferent communications busses (e.g., a system bus 554, zone buses556-560 and 564, sensor/actuator bus 566, etc.) and across multipledifferent communications protocols. In some embodiments, equipmentdiscovery is accomplished using active node tables, which provide statusinformation for devices connected to each communications bus. Forexample, each communications bus can be monitored for new devices bymonitoring the corresponding active node table for new nodes. When a newdevice is detected, BMS 500 can begin interacting with the new device(e.g., sending control signals, using data from the device) without userinteraction.

Some devices in BMS 500 present themselves to the network usingequipment models. An equipment model defines equipment objectattributes, view definitions, schedules, trends, and the associatedBACnet value objects (e.g., analog value, binary value, multistatevalue, etc.) that are used for integration with other systems. Somedevices in BMS 500 store their own equipment models. Other devices inBMS 500 have equipment models stored externally (e.g., within otherdevices). For example, a zone coordinator 508 can store the equipmentmodel for a bypass damper 528. In some embodiments, zone coordinator 508automatically creates the equipment model for bypass damper 528 or otherdevices on zone bus 558. Other zone coordinators can also createequipment models for devices connected to their zone busses. Theequipment model for a device can be created automatically based on thetypes of data points exposed by the device on the zone bus, device type,and/or other device attributes. Several examples of automatic equipmentdiscovery and equipment model distribution are discussed in greaterdetail below.

Still referring to FIG. 5, BMS 500 is shown to include a time varyingperformance indication system 502, a system manager 503; several zonecoordinators 506, 508, 510 and 518; and several zone controllers 524,530, 532, 536, 548, and 550. System manager 503 can monitor various datapoints in BMS 500 and report monitored variables to time varyingperformance indication system 502. System manager 503 can communicatewith client devices 504 (e.g., user devices, desktop computers, laptopcomputers, mobile devices, etc.) via a data communications link 574(e.g., BACnet IP, Ethernet, wired or wireless communications, etc.).System manager 503 can provide a user interface to client devices 504via data communications link 574. The user interface may allow users tomonitor and/or control BMS 500 via client devices 504.

In some embodiments, system manager 503 is connected with zonecoordinators 506-510 and 518 via a system bus 554. System manager 503can be configured to communicate with zone coordinators 506-510 and 518via system bus 554 using a master-slave token passing (MSTP) protocol orany other communications protocol. System bus 554 can also connectsystem manager 503 with other devices such as a constant volume (CV)rooftop unit (RTU) 512, an input/output module (TOM) 514, a thermostatcontroller 516 (e.g., a TEC5000 series thermostat controller), and anetwork automation engine (NAE) or third-party controller 520. RTU 512can be configured to communicate directly with system manager 503 andcan be connected directly to system bus 554. Other RTUs can communicatewith system manager 503 via an intermediate device. For example, a wiredinput 562 can connect a third-party RTU 542 to thermostat controller516, which connects to system bus 554.

System manager 503 can provide a user interface for any devicecontaining an equipment model. Devices such as zone coordinators 506-510and 518 and thermostat controller 516 can provide their equipment modelsto system manager 503 via system bus 554. In some embodiments, systemmanager 503 automatically creates equipment models for connected devicesthat do not contain an equipment model (e.g., TOM 514, third partycontroller 520, etc.). For example, system manager 503 can create anequipment model for any device that responds to a device tree request.The equipment models created by system manager 503 can be stored withinsystem manager 503. System manager 503 can then provide a user interfacefor devices that do not contain their own equipment models using theequipment models created by system manager 503. In some embodiments,system manager 503 stores a view definition for each type of equipmentconnected via system bus 554 and uses the stored view definition togenerate a user interface for the equipment.

Each zone coordinator 506-510 and 518 can be connected with one or moreof zone controllers 524, 530-532, 536, and 548-550 via zone buses 556,558, 560, and 564. Zone coordinators 506-510 and 518 can communicatewith zone controllers 524, 530-532, 536, and 548-550 via zone busses556-560 and 564 using a MSTP protocol or any other communicationsprotocol. Zone busses 556-560 and 564 can also connect zone coordinators506-510 and 518 with other types of devices such as variable air volume(VAV) RTUs 522 and 540, changeover bypass (COBP) RTUs 526 and 552,bypass dampers 528 and 546, and PEAK controllers 534 and 544.

Zone coordinators 506-510 and 518 can be configured to monitor andcommand various zoning systems. In some embodiments, each zonecoordinator 506-510 and 518 monitors and commands a separate zoningsystem and is connected to the zoning system via a separate zone bus.For example, zone coordinator 506 can be connected to VAV RTU 522 andzone controller 524 via zone bus 556. Zone coordinator 508 can beconnected to COBP RTU 526, bypass damper 528, COBP zone controller 530,and VAV zone controller 532 via zone bus 558. Zone coordinator 510 canbe connected to PEAK controller 534 and VAV zone controller 536 via zonebus 560. Zone coordinator 518 can be connected to PEAK controller 544,bypass damper 546, COBP zone controller 548, and VAV zone controller 550via zone bus 564.

A single model of zone coordinator 506-510 and 518 can be configured tohandle multiple different types of zoning systems (e.g., a VAV zoningsystem, a COBP zoning system, etc.). Each zoning system can include aRTU, one or more zone controllers, and/or a bypass damper. For example,zone coordinators 506 and 510 are shown as Verasys VAV engines (VVEs)connected to VAV RTUs 522 and 540, respectively. Zone coordinator 506 isconnected directly to VAV RTU 522 via zone bus 556, whereas zonecoordinator 510 is connected to a third-party VAV RTU 540 via a wiredinput 568 provided to PEAK controller 534. Zone coordinators 508 and 518are shown as Verasys COBP engines (VCEs) connected to COBP RTUs 526 and552, respectively. Zone coordinator 508 is connected directly to COBPRTU 526 via zone bus 558, whereas zone coordinator 518 is connected to athird-party COBP RTU 552 via a wired input 570 provided to PEAKcontroller 544.

Zone controllers 524, 530-532, 536, and 548-550 can communicate withindividual BMS devices (e.g., sensors, actuators, etc.) viasensor/actuator (SA) busses. For example, VAV zone controller 536 isshown connected to networked sensors 538 via SA bus 566. Zone controller536 can communicate with networked sensors 538 using a MSTP protocol orany other communications protocol. Although only one SA bus 566 is shownin FIG. 5, it should be understood that each zone controller 524,530-532, 536, and 548-550 can be connected to a different SA bus. EachSA bus can connect a zone controller with various sensors (e.g.,temperature sensors, humidity sensors, pressure sensors, light sensors,occupancy sensors, etc.), actuators (e.g., damper actuators, valveactuators, etc.) and/or other types of controllable equipment (e.g.,chillers, heaters, fans, pumps, etc.).

Each zone controller 524, 530-532, 536, and 548-550 can be configured tomonitor and control a different building zone. Zone controllers 524,530-532, 536, and 548-550 can use the inputs and outputs provided viatheir SA busses to monitor and control various building zones. Forexample, a zone controller 536 can use a temperature input received fromnetworked sensors 538 via SA bus 566 (e.g., a measured temperature of abuilding zone) as feedback in a temperature control algorithm. Zonecontrollers 524, 530-532, 536, and 548-550 can use various types ofcontrol algorithms (e.g., state-based algorithms, extremum seekingcontrol (ESC) algorithms, proportional-integral (PI) control algorithms,proportional-integral-derivative (PID) control algorithms, modelpredictive control (MPC) algorithms, feedback control algorithms, etc.)to control a variable state or condition (e.g., temperature, humidity,airflow, lighting, etc.) in or around building 10.

Time Varying Performance Indication System of Generating PerformanceIndex for Connected Equipment

Referring now to FIG. 6, a block diagram of another building managementsystem (BMS) 600 which includes the time varying performance indicationsystem for generating a performance index for connected equipment isshown, according to some embodiments. BMS 600 can include many of thesame components as BMS 400 and BMS 500 as described with reference toFIGS. 4 and 5. For example, BMS 600 is shown to include building 10,network 446, client devices 448, and time varying performance indicationsystem 502. Building 10 is shown to include connected equipment 610,which can include any type of equipment used to monitor and/or controlbuilding 10. Connected equipment 610 can include connected chillers 612,connected AHUs 614, connected actuators 616, connected controllers 618,or any other type of equipment in a building HVAC system (e.g., boilers,economizers, valves, dampers, cooling towers, fans, pumps, etc.) orbuilding management system (e.g., lighting equipment, securityequipment, refrigeration equipment, etc.). Connected equipment 610 caninclude any of the equipment of HVAC system 100, waterside system 200,airside system 300, BMS 400, and/or BMS 500, as described with referenceto FIGS. 1-5.

Connected equipment 610 can be outfitted with sensors to monitorparticular conditions of the connected equipment 610. For example,chillers 612 can include sensors configured to monitor chiller variablessuch as chilled water return temperature, chilled water supplytemperature, chilled water flow status (e.g., mass flow rate, volumeflow rate, etc.), condensing water return temperature, condensing watersupply temperature, motor amperage (e.g., of a compressor, etc.),variable speed drive (VSD) output frequency, and refrigerant properties(e.g., refrigerant pressure, refrigerant temperature, condenserpressure, evaporator pressure, etc.) at various locations in therefrigeration circuit. An example of a chiller 700 which can be used asone of chillers 612 is described in greater detail with reference toFIG. 7. Similarly, AHUs 614 can be outfitted with sensors to monitor AHUvariables such as supply air temperature and humidity, outside airtemperature and humidity, return air temperature and humidity, chilledfluid temperature, heated fluid temperature, damper position, etc. Ingeneral, connected equipment 610 monitor and report variables thatcharacterize the performance of the connected equipment 610. Eachmonitored variable can be forwarded to network control engine 608 as adata point (e.g., including a point ID, a point value, etc.).

Monitored variables can include any measured or calculated valuesindicating the performance of connected equipment 610 and/or thecomponents thereof. For example, monitored variables can include one ormore measured or calculated temperatures (e.g., refrigeranttemperatures, cold water supply temperatures, hot water supplytemperatures, supply air temperatures, zone temperatures, etc.),pressures (e.g., evaporator pressure, condenser pressure, supply airpressure, etc.), flow rates (e.g., cold water flow rates, hot water flowrates, refrigerant flow rates, supply air flow rates, etc.), valvepositions, resource consumptions (e.g., power consumption, waterconsumption, electricity consumption, etc.), control setpoints, modelparameters (e.g., regression model coefficients, etc.), and/or any othertime-series values that provide information about how the correspondingsystem, device, and/or process is performing. Monitored variables can bereceived from connected equipment 610 and/or from various componentsthereof. For example, monitored variables can be received from one ormore controllers (e.g., BMS controllers, subsystem controllers, HVACcontrollers, subplant controllers, AHU controllers, device controllers,etc.), BMS devices (e.g., chillers, cooling towers, pumps, heatingelements, etc.), and/or collections of BMS devices.

Connected equipment 610 can also report equipment status information.Equipment status information can include, for example, the operationalstatus of the equipment, an operating mode (e.g., low load, medium load,high load, etc.), an indication of whether the equipment is runningunder normal or abnormal conditions, a safety fault code, and/or anyother information that indicates the current status of connectedequipment 610. In some embodiments, equipment status informationreported by the connected equipment 610 is in the form of status codes.For example, four types of status codes can be reported by a connectedequipment (e.g., chiller), including safety shutdown codes (safetycodes), warning codes, cycling codes, and operation codes. The statuscodes are described in greater detail herein below in this disclosure.

In some embodiments, each device of connected equipment 610 includes acontrol panel (e.g., control panel 710 shown in FIG. 7). The controlpanel can use the sensor data to shut down the device if the controlpanel determines that the device is operating under unsafe conditions.For example, the control panel can compare the sensor data (or a valuederived from the sensor data) to predetermined thresholds. If the sensordata or calculated value crosses a safety threshold, the control panelcan shut down the device and/or operate the device at a deratedsetpoint. The control panel can generate a data point when a safety shutdown or a derate occurs. The data point can include a safety fault codewhich indicates the reason or condition that triggered the shut down orderate.

Connected equipment 610 can provide monitored variables and equipmentstatus information to a network control engine 608. Network controlengine 608 can include a building controller (e.g., BMS controller 366),a system manager (e.g., system manager 503), a network automation engine(e.g., NAE 520), or any other system or device of building 10 configuredto communicate with connected equipment 610. In some embodiments, themonitored variables and the equipment status information are provided tonetwork control engine 608 as data points. Each data point can include apoint ID and/or a point value. The point ID can identify the type ofdata point and/or a variable measured by the data point (e.g., condenserpressure, refrigerant temperature, fault code, etc.). Monitoredvariables can be identified by name or by an alphanumeric code (e.g.,Chilled_Water_Temp, 7694, etc.). The point value can include analphanumeric value indicating the current value of the data point (e.g.,44° F., fault code 4, etc.).

Network control engine 608 can broadcast the monitored variables and theequipment status information to a remote operations center (ROC) 602.ROC 602 can provide remote monitoring services and can send an alert tobuilding 10 in the event of a critical alarm. ROC 602 can push themonitored variables and equipment status information to a reportingdatabase 604, where the data is stored for reporting and analysis. Timevarying performance indication 502 can access database 604 to retrievethe monitored variables and the equipment status information.

In some embodiments, time varying performance indication 502 is acomponent of BMS controller 366 (e.g., within FDD layer 416). Forexample, time varying performance indication system 502 can beimplemented as part of a METASYS® brand building automation system, assold by Johnson Controls Inc. In other embodiments, time varyingperformance indication system 502 can be a component of a remotecomputing system or cloud-based computing system configured to receiveand process data from one or more building management systems. Forexample, time varying performance indication system 502 can connect theconnected equipment 610 (e.g., chillers 612) to the cloud and collectreal-time data for over a number of points (e.g., 50 points) on thoseequipment. In other embodiments, time varying performance indicationsystem 502 can be a component of a subsystem level controller (e.g., aHVAC controller, etc.), a subplant controller, a device controller(e.g., AHU controller 330, a chiller controller, etc.), a fieldcontroller, a computer workstation, a client device, and/or any othersystem and/or device that receives and processes monitored variablesfrom connected equipment 610.

Time varying performance indication system 502 may use the monitoredvariables to identify a current operating state of connected equipment610. The current operating state can be examined by time varyingperformance indication system 502 to expose when connected equipment 610begins to degrade in performance and/or to predict when faults willoccur. In some embodiments, time varying performance indication system502 determines whether the current operating state is a normal operatingstate or a faulty operating state. Time varying performance indicationsystem 502 may report the current operating state and/or the predictedfaults to client devices 448, service technicians 606, building 10,and/or any other system and/or device. Communications between timevarying performance indication 502 and other systems and/or devices canbe direct and/or via an intermediate communications network, such asnetwork 446. If the current operating state is identified as a faultystate or moving toward a faulty state, time varying performanceindication system 502 may generate an alert or notification for servicetechnicians 606 to repair the fault or potential fault before it becomesmore severe. In some embodiments, time varying performance indicationsystem 502 uses the current operating state to determine an appropriatecontrol action for connected equipment 610.

In some embodiments, time varying performance indication system 502provides a web interface which can be accessed by service technicians606, client devices 448, and other systems or devices. The web interfacecan be used to access the raw data in reporting database 604, view theresults produced by the time varying performance indication system,identify which equipment is in need of preventative maintenance, andotherwise interact with time varying performance indication system 502.Service technicians 606 can access the web interface to view a list ofequipment for which faults are predicted by time varying performanceindication system 502. Service technicians 606 can use the predictedfaults to proactively repair connected equipment 610 before a faultand/or an unexpected shut down occurs. These and other features of timevarying performance indication system 502 are described in greaterdetail below.

Referring now to FIG. 7, a schematic diagram of a chiller 700 is shown,according to some embodiments. Chiller 700 is an example of a type ofconnected equipment 610 which can report monitored variables and statusinformation (status codes) to time varying performance indication system502. Chiller 700 is shown to include a refrigeration circuit having acondenser 702, an expansion valve 704, an evaporator 706, a compressor708, and a control panel 710. In some embodiments, chiller 700 includessensors that measure a set of monitored variables at various locationsalong the refrigeration circuit. Table 1 describes an exemplary set ofmonitored parameters/variables that can be measured in chiller 700. Timevarying performance indication system 502 can use these or othervariables to detect the current operating state of chiller 700, detectfaults, predict potential/future faults, and/or determine diagnoses.Time varying performance indication system 502 may additionally useexternal parameters such as weather conditions and geographical locationwhere the chiller 700 is operating.

TABLE 1 Monitored Chiller Parameters Number ID Description 1 MOT-FLAMotor full load amps 2 CHWR-T Chilled water return temperature 3 CHWS-TChilled water supply temperature 4 COND-P Condenser pressure 5 EVAP-PEvaporator pressure 6 CWR-T Condensed water return temperature 7 CWS-TCondensed water supply temperature 8 MTAMP-SP Motor amps setpoint 9CHWT-SP Chilled water supply temperature setpoint 10 VFD OP-Hz Variablefrequency drive output frequency 11 CHWF-STS Chilled water flow status

Chiller 700 can be configured to operate in multiple different operatingstates. For example, chiller 700 can be operated in a low load state, amedium load state, a high load state, and/or various statestherebetween. The operating states may represent the normal operatingstates or conditions of chiller 700. Faults in chiller 700 may cause theoperation of chiller 700 to deviate from the normal operating states.For example, various types of faults may occur in each of the normaloperating states. For example, faults can be caused by stalling orsurging in the compressor or other mechanical effects that can occurduring operation. In some embodiments, time varying performanceindication system 502 can collect or receive samples of the monitoredvariables. For example, system 502 may collect or receive 1000 samplesof the monitored variables at a rate of one sample per second.

Referring now to FIG. 8, a block diagram illustrating the time varyingperformance indication system 502 in greater detail is shown, accordingto some embodiments. Time varying performance indication system 502 isshown to include a communications interface 810 and a processing circuit812. Communications interface 810 may facilitate communications betweentime varying performance indication system 502 and various externalsystems or devices. For example, time varying performance indicationsystem 502 may receive the monitored variables from connected equipment610 and provide control signals, performance indices, and/or otherinformation of detected faults to connected equipment 610 viacommunications interface 710. Communications interface 710 may also beused to communicate with remote systems and applications 444, clientdevices 448, and/or any other external system or device. For example,time varying performance indication system 502 may provide performanceindices and other information of detected faults to remote systems andapplications 444, client devices 448, service technicians 606, or anyother external system or device via communications interface 810.

Communications interface 810 can include any number and/or type of wiredor wireless communications interfaces (e.g., jacks, antennas,transmitters, receivers, transceivers, wire terminals, etc.). Forexample, communications interface 810 can include an Ethernet card andport for sending and receiving data via an Ethernet-based communicationslink or network. As another example, communications interface 810 caninclude a WiFi transceiver, a NFC transceiver, a cellular transceiver, amobile phone transceiver, or the like for communicating via a wirelesscommunications network. In some embodiments, communications interface810 includes RS232 and/or RS485 circuitry for communicating with BMSdevices (e.g., chillers, controllers, etc.). Communications interface810 can be configured to use any of a variety of communicationsprotocols (e.g., BACNet, Modbus, N2, MSTP, Zigbee, etc.). Communicationsvia interface 810 can be direct (e.g., local wired or wirelesscommunications) or via an intermediate communications network 446 (e.g.,a WAN, the Internet, a cellular network, etc.). Communications interface810 can be communicably connected with processing circuit 812, and thevarious components thereof can send and receive data via communicationsinterface 810.

Processing circuit 812 is shown to include a processor 814 and memory816. Processor 814 can be implemented as a general purpose processor, anapplication specific integrated circuit (ASIC), one or more fieldprogrammable gate arrays (FPGAs), a group of processing components, orother suitable electronic processing components. Memory 816 (e.g.,memory, memory unit, storage device, etc.) can include one or moredevices (e.g., RAM, ROM, Flash memory, hard disk storage, etc.) forstoring data and/or computer code for completing or facilitating thevarious processes, layers and modules described in the presentapplication. Memory 816 can be or include volatile memory ornon-volatile memory. Memory 816 can include database components, objectcode components, script components, or any other type of informationstructure for supporting the various activities and informationstructures described in the present application. According to someembodiments, memory 816 is communicably connected to processor 814 viaprocessing circuit 812 and includes computer code for executing (e.g.,by processing circuit 812 and/or processor 814) one or more processesdescribed herein.

Still referring to FIG. 8, in some embodiments, the memory 816 caninclude at least an input processing module 820, a performance checkmodule 822, an individual performance check indicator generation module824, an overall performance index generation module 826, a first weightsdetermination module 828, and a second weights determination module 830.In other embodiments, more, less, or different modules or components canbe stored in memory 816. In some embodiments, the modules 820-830 can beimplemented in one apparatus. In other embodiments, each of the modules820-830 can be implemented in different and separate apparatuses and/orexecuted by different and separate processors, or a combination thereof.In some embodiments, modules 820-830 stored in a non-transitory computerreadable medium (e.g., memory 816) can be executed by the processor 814to perform operations as described herein. In some embodiments, each ofthe modules 820-830 or a combination of some of the modules 820-830 canbe implemented as hardware circuits.

Referring now to FIG. 9, a high level flow diagram illustrating aprocess 900 of generating a performance index for connected equipment isshown, according to some embodiments. In some embodiments, at stage 902,the time varying performance indication system 502 can be configured toobtain time series data from past N time units and connected equipmentspecific design parameters. For example, the input processing module 820can be configured to obtain time series data and connected equipmentspecific design parameters. The time units can be days, hours, minutes,seconds, weeks, months, or years. N is a number, such as an integer. Forexample, the past N time units can be the past 5 days, past 2 weeks,etc. In some embodiments, the time series data can include data pointsof a plurality of monitored variables and a plurality of status codesfrom the connected equipment 610.

In some embodiments, the connected equipment 610 can be configured tomeasure a plurality of monitored variables and generate a plurality ofstatus codes. As discussed herein above in relation to FIGS. 6 and 7,connected equipment 610 (e.g., chillers 612, 700) can measure monitoredvariables (e.g., measured or calculated temperatures, pressures, flowrates, valve positions, resource consumptions, control setpoints, modelparameters) that can be any time-series values providing informationabout how the corresponding system, device, and/or process isperforming. Connected equipment 610 can also provide or generateequipment status information in the form of status codes. In someembodiments, four types of status codes can be provided and reported byconnected equipment (e.g., chiller), including safety shutdown codes(safety codes), warning codes, cycling codes, and operation codes. Inthe descriptions herein below, a chiller (e.g., chiller 612, 700) isused as an example of the connected equipment 610. It should beunderstood that connected equipment is not limited to chillers and theoperations described herein below can be performed for any connectedequipment.

In some embodiments, safety shutdown codes are generated when safetyshutdowns occur. Safety shutdowns can be triggered when certainconditions that are deemed dangerous to a chiller occur. Theseconditions may cause physical damage to the evaporator, condenser,compressor, variable speed drive (VSD), motor, or other components ofthe chiller. By the time a safety shutdown occurs, the chiller may havealready sustained some damage. In some embodiments, depending on whatcauses the safety shutdown, it may require time and money to do ashutdown and machine servicing, or it could just require a reset of achiller panel or building control strategy. In some embodiments, knowingthe type of safety shutdown may not be sufficient to determine the rootcause and solution. In some embodiments, warning codes do not shut downthe chiller but give alerts that the chiller is not operating under agood condition. In some embodiments, cycling codes generally shut down achiller due to specific conditions that occur in the chiller. Forexample, if a pump that feeds the condenser fails, the chiller may shutdown due to loss of condenser flow. In some embodiments, operation codesindicate if the chiller is running, not running, or in alarm or shutdownstates. In some embodiments, there are a number of different safetycodes, warning codes, and cycling codes that can occur. In someembodiments, the operation codes are limited to a maximum number (e.g.,15) and a subset (e.g., 3) represents states when the chiller isrunning.

In some embodiments, the input processing module 820 of the time varyingperformance indication system 502 can receive or obtain time series data(e.g., data points of the plurality of monitored variables and theplurality of status codes) from the connect equipment 610 through thecommunication interface 810 via the network 446. In some embodiments,the communication interface 810 can obtain the time series data from thereporting database 604. Table 2 shows an example of the time series datathat can be used as inputs to the operations performed by the timevarying performance indication system 502. In some embodiments, the datais collected from sensors and is related to physical quantities in thechiller. For example, for legacy chillers, points may be sampled every1, 5, or 15 minutes, in some embodiments. For other chillers (e.g., SCCchillers), points may be change-of-value, in some embodiments.

TABLE 2 Sample Input Data varname timestamp ACC OP HRS ACC SYS STRTCHWF-STS CHWP-STS CHWR-T 2018-07-09 11377.0 885.0 0.0 0.0 13.7 00:45:002018-07-09 11377.0 885.0 0.0 0.0 13.8 01:00:00 2018-07-09 11377.0 885.00.0 0.0 13.8 01:15:00 2018-07-09 11377.0 885.0 0.0 0.0 13.7 01:30:002018-07-09 11377.0 885.0 0.0 0.0 13.7 01:45:00 varname timestamp CHWS-TCHWT-SP COND-AP COND-P CSAT-T 2018-07-09 12.9 6.7 −10.499999 368.9 13.800:45:00 2018-07-09 12.9 6.7 −10.499999 369.6 13.8 01:00:00 2018-07-0913.0 7.3 −10.40001 369.6 13.8 01:15:00 2018-07-09 12.8 7.4 −10.40001370.3 13.8 01:30:00 2018-07-09 12.8 7.4 −10.30001 370.3 13.9 01:45:00varname timestamp VSD OP-Hz VSD OP-V VSD PH A-C VSD PH B-C VSD PH C-C2018-07-09 0.0 0.0 0.0 0.0 0.0 00:45:00 2018-07-09 0.0 0.0 0.0 0.0 0.001:00:00 2018-07-09 0.0 0.0 0.0 0.0 0.0 01:15:00 2018-07-09 0.0 0.0 0.00.0 0.0 01:30:00 2018-07-09 0.0 0.0 0.0 0.0 0.0 01:45:00 varnametimestamp VSD-CONVHS-T VSD-SURG-CONT VSDDC-V VSDIA-T WAR-CODE 2018-07-0923.0 943.0 1.0 31.0 0.0 00:45:00 2018-07-09 23.0 943.0 1.0 31.0 0.001:00:00 varname timestamp ACC OP HRS ACC SYS STRT CHWF-STS CHWP-STSCHWR-T 2018-07-09 23.0 943.0 1.0 31.0 0.0 01:15:00 2018-07-09 23.0 943.01.0 31.0 0.0 01:30:00 2018-07-09 23.0 943.0 1.0 31.0 0.0 01:45:00

As illustrated in Table 2 above, each input data or time series data caninclude a value and a timestamp indicating the time that the data iscollected. For example, chilled water flow status (varname or ID:CHWP-STS) for this particular chiller has a value of 0.0 at the time2018-07-09 00:45:00. It should be understood that the example input dataas shown in Table 2 are for illustrative purposes only and should not beregarded as limiting in any way.

In some embodiments, the input processing module 820 of the time varyingperformance indication system 502 can obtain or receive connectedequipment specific parameters. The connected equipment specificparameters are parameters specific to the connected equipment (e.g.chiller 612, 700). In some embodiments, the connected equipment specificparameters are obtained from the reporting database 604 via thecommunication interface 810. In some embodiments, the connectedequipment specific parameters are obtained from another system orstorage via the network 446 through the communication interface 810. Insome embodiments, the connected equipment specific parameters are storedin a memory or local storage of the time varying performance indicationsystem 502. Example connected equipment specific parameters areillustrated with reference to Table 3 below.

Referring again to FIG. 9, in some embodiments, at stage 904, the timevarying performance indication system 502 can be configured to perform aplurality of performance checks for the connected equipment using thetime series data (e.g., data points of the plurality of monitoredvariables and the plurality of status codes) and connected equipmentspecific parameters obtained or received at stage 902. For example, theperformance check module 822 can perform the performance checks for theconnected equipment. In some embodiments, the performance checks includestatus checks (first performance checks) and health checks (secondperformance checks). In other embodiments, additional performance checks(e.g., raw sensor value checks, monitoring of long-term trends, setpointdeviations, vibration data, flow measuments, or any other checks withrelevance to connected equipment health) can be performed for theconnected equipment in addition to the status checks and health checks.

In some embodiments, the time varying performance indication system 502(e.g., the performance check module 822) can perform a plurality ofstatus checks for the connected equipment using a plurality of statuscodes from the past N time units (e.g., past 5 days). In someembodiments, the performance check module 822 can identify safetyshutdown codes (safety codes), warning codes, and cycling codesgenerated by the connected equipment. For example, the safety codes,warning codes, and cycling codes in the past 5 days can be identified bychecking the timestamps associated with each code.

In some embodiments, the time varying performance indication system 502(e.g., the performance check module 822) can perform a plurality ofhealth checks for the connected equipment using data points of theplurality of monitored variables from the past N time units (e.g., past12 hours, past 5 days, past 2 weeks), a plurality of connected equipmentspecific parameters, and a plurality of predetermined rules. Forexample, the data points of the plurality of monitored variables fromthe past N time units and the plurality of connected equipment specificparameters obtained in stage 902 can be applied to a plurality ofpredetermined rules that are described in more detail below.

In some embodiments, the performance check module 822 can check a set ofpredetermined rules to determine if there is a violation of any of therules. Responsive to a violation of one or more rules, the performancecheck module 822 can generate alerts or alarms depending on the degreeof the severity of the violation and/or the rule being violated.Different connected equipment may have different health checks. Ingeneral, the health checks available for a certain connected equipmentdepend on the type of the connected equipment and customerconfigurations. Continuing using the example of the chiller as theconnected equipment, in some embodiments, the performance check module822 may consider a subset of the health checks that are used for theparticular type of the chiller because not all health checks apply toevery chiller. Table 3 shows a list of health check parameters(connected equipment specific parameters) and constants (thresholds) fora particular type of chiller as an illustrative example.

TABLE 3 Health check parameter and constant list for a type of chillers.Parameter Value Alert Alarm % FLA-MIN 10 Condenser 3.5 5 Approach VSD -High Internal 135 140 Amb. Temp. Low Refrigerant 15 10 Level Cond Ent.Water 85 Evaporator 3.5 5 Approach High Oil Temp. 155 165 RuntimeThreshold- 24 (HealthChart) High Refrigerant 90 Level Low condenser 4947 water entering temp. Runtime Threshold 0.3 0.3 % - Condenser ApproachRuntime Threshold 0.3 0.3 % - VSD - High Internal Amb. temp RuntimeThreshold 0.5 0.5 % - Low Refrigerant Level Runtime Threshold 0.05 % -Cond Ent.Water Runtime Threshold 0.3 0.3 % - Evaporator Approach RuntimeThreshold 0.05 0.05 % - High Oil Temp. Runtime Threshold 0.05 % - HighRefrigerant Level Runtime Threshold 0.95 % - VSD Capacity Control AlarmRuntime Threshold 0.05 % - Low condenser water entering temp.

In some embodiments, for example, using the parameters and constants(thresholds) in Table 3, the performance check module 822 applies thefollowing predetermined rules to perform the health checks.

1. High evaporator approach temperature:

-   -   (MOT-FLA>Const(% FLA-MIN)) AND (EVAP-AP>Const(Evaporator        Approach))        2. High condenser approach temperature:    -   (MOT-FLA>Const(% FLA-MIN)) AND (COND-AP>Const(Condenser        Approach))        3. High entering condenser water temperature:    -   (MOT-FLA>Const(% FLA-MIN)) AND (CWS-T>Const(Cond Ent.Water))        4. High condenser refrigerant level:    -   (MOT-FLA>Const(% FLA-MIN)) AND (REF-POS>Const(High Refrigerant        Level))        5. Low condenser refrigerant level:    -   (MOT-FLA>Const(% FLA-MIN)) AND (REF-POS<Const(Low Refrigerant        Level)) AND (CHWR-T-CHWS-T>1.5)        6. High oil temperature while running:    -   (MOT-FLA>Const(% FLA-MIN)) AND (OILS-T>Const(High Oil Temp.))        7. Low entering condenser water temperature:    -   (MOT-FLA>Const(% FLA-MIN)) AND (CWS-T<Const(Low condenser water        entering temp.))

In the above example health check rules, evaluated data points arelimited to those collected while the chiller was running. For example,these data points must have operation codes that correspond to “running”states (e.g., 8, 9, 12) and have the motor percent full load amps valuesabove Const(% FLA-MIN). As shown in Table 3, the value of (% FLA-MIN)=10in this example. In some embodiments, the number of these data pointssets the “Run Time.” In some embodiments, “Alert Time” and “Alarm Time”indicate the number of data points where the chiller is running and isin alert and alarm conditions, respectively. For example, if the “AlertTime”/“Run Time” value exceeds the threshold listed in Table 3, thechiller is in Alert, and this health check is triggered. As an example,with respect to the first example health check rule for high evaporatorapproach temperature, an alert is triggered when the motor percent fullload amps value (MOT-FLA) is above 10 and the evaporator approach(EVAP-AP) value is greater than 3.5. Continuing with this example, analarm is triggered when the motor percent full load amps value (MOT-FLA)is above 10 and the evaporator approach (EVAP-AP) value is greater than5.

In some embodiments, the time varying performance indication system 502can determine a plurality of individual performance check indicatorsbased on the status checks and the health checks using a plurality offirst weights. For example, the individual performance check indicatorgeneration module 824 can be configured to determine individualperformance check indicators based on the status checks and the healthchecks. In some embodiments, the first weights are time based weightseach determined based on a different timing. Example individualperformance check indicators generation or determination processes aredescribed in more detail in relation to FIGS. 11 and 12.

Referring now to FIG. 11, a flow diagram illustrating a process 1100 ofgenerating a performance index for connected equipment is shown,according to some embodiments. In brief overview, a window of timeseries data can be provided as input, and a number of performance checkscan be applied to it. In some embodiments, each of the performancechecks returns a 0 if it passes, or a 1 if it fails. The values are thenmultiplied by their respective weights to obtain a penalty factor foreach check. Performance check weights reflect the severity or impact ofthe problems they detect, and may also be time dependent if, forexample, the recent events are weighted more heavily than events thattook place several days ago. The penalty factors are then summed andsubtracted from the maximum value of the index, I_(max) (e.g., 10, 100)to obtain the value of the performance index. In some embodiments, whilethe index decreases with each performance check violation, it isconstrained to stay above 0.

Referring to FIG. 11, in further detail, at stage 1104, a plurality (nnumbers) of performance checks (e.g., status checks, health checks) areperformed as described with reference to stage 904 of FIG. 9. In someembodiments, an individual performance check indicator (e.g., f_(1,t), .. . f_(n,t)) may be generated as a result of the respective performancecheck. For example, f_(n,t)=0 if the respective performance checkpasses, and f_(n,t)=1 if the respective performance check fails (e.g.,an alert or alarm is triggered with respect to the health checks, ashutdown, warning, etc. are identified with respect to the statuschecks). In some embodiments, the individual performance check indicatoris used with weights w₁ . . . w_(n) (second weights as described hereinbelow) to generate the overall performance index. In the embodiments ofthe individual performance check indicator determination or generationprocess as shown in FIG. 11, the individual performance check indicator(e.g., f_(1,t), . . . f_(n,t)) has binary values (e.g., pass, fail). Inother embodiments, the individual performance check indicator may have aseries of values associated with time varying weights (first weights),as illustrated in relation to FIG. 12.

Referring now to FIG. 12, a flow diagram illustrating a process 1200 ofgenerating a performance index for connected equipment is shown,according to some embodiments. FIG. 12 is similar to the FIG. 11, with adifferent embodiment for the individual performance check indicator(e.g., f_(1,t), . . . f_(n,t)) generation or determination process.Referring to FIG. 12, at stage 1204, a plurality (n numbers) ofperformance checks (e.g., status checks, health checks) are performed asdescribed with reference to stage 904 of FIG. 9. In the embodiments ofFIG. 12, the individual performance check indicators (e.g., f_(1,t), . .. f_(n,t)) are time dependent when data from a period of time or rangeof days are considered. As shown in stage 1204 of FIG. 12, individualperformance check indicators have different values based on when theevents (e.g., an alert or alarm with respect to the health checks, ashutdown, warning, etc. are identified with respect to the statuschecks) occurred. For example, most recent events may be weightedheavier than earlier events during the past N time units (e.g., past 5days). As shown in the examples of FIG. 12, the individual performancecheck indicator (e.g., f_(1,t), . . . f_(n,t)) decreases in valuedepending upon when the event is last happened. In the embodiments ofFIG. 12, a set of time varying weights (first weights) 0, 0.14, 0.22,0.367, 0.606, 1.0 are used for the individual performance checkindicators. For example, f_(n,t)=0 if no occurrence of the event in past120 hours, f_(n,t)=0.14 if last occurrence is between 96 and 120 hours,f_(n,t)=0.22 if last occurrence is between 72 and 96 hours,f_(n,t)=0.367 if last occurrence is between 48 and 72 hours,f_(n,t)=0.606 if last occurrence is between 24 and 48 hours, andf_(n,t)=1 if last occurrence is between 0 and 24 hours.

In some embodiments, the first weights determination module 828 candetermine the first weights used for the individual performance checkindicators. For example, the first weights can be the time varyingweights used for the individual performance check indicators describedabove in relation to FIG. 12. In some embodiments, the time varyingweights are determined using the exponential decay function with a tauvalue of two. FIG. 13 shows a graph 1300 of the exponential decayfunction with a tau value of two, according to some embodiments. Asshown in FIG. 13, the X-axis represents time and the dots show valuesused. In other embodiments, different methods can be used to determinethe first weights or the time varying weights.

Referring back to FIG. 9, in some embodiments, at stage 906, the timevarying performance indication system 502 can be configured to generatean overall performance index for the connected equipment using theplurality of individual performance check indicators and a plurality ofsecond weights. For example, the overall performance index generationmodule 826 can generate an overall performance index for the connectedequipment. In some embodiments, an overall performance index in the formof a number index value (0-I_(max)) is produced at stage 908, whereI_(max) is a positive number (e.g., 10, 100), in some embodiments. FIGS.10, 11 and 12 include a more detailed illustration of the overallperformance index generation.

Referring now to FIG. 10, a flow diagram illustrating a process 1000 ofgenerating a performance index for connected equipment is shown,according to some embodiments. Stages 1002, 1004 and 1008 can beidentical or similar to stages 902, 904 and 908 as described withrespect to FIG. 9 and will not be describe here again. Referring to FIG.10, in some embodiments, at stage 1006, a plurality of individualperformance check indicators 1006 a and a plurality of second weights1006 b are used to produce overall performance index. For example, theindividual performance check indicators described herein above inrelation to FIGS. 11 and 12 can be used to generate the overallperformance index. In some embodiments, the overall performance index iscalculated as the summation of the products of all of the performancechecks (individual performance check indicators) and their correspondingseverity weights, and then subtracting this value from the I_(max). Insome embodiments, the I_(max) is a positive number (e.g., 10, 100).

In some embodiments, the following equation (also as shown in stages1106 and 1206 of FIGS. 11 and 12) can be used to generate the overallperformance index for the connected equipment.

I _(t)=max(0,I _(max)−Σ_(i=0) ^(n) w _(i) f _(i,t))  (1)

where I_(t) is the value of the performance index at time t, f_(i,t)represents the ith individual performance check indicator (performancecheck) of a total n number individual performance check indicators(performance checks) at time t, and W_(i) represents the weight (secondweight) for the corresponding (ith) individual performance checkindicator f_(i,t). It should be understood that the performance indexformula as shown above is only one of several possible implementationsand should not be regarded as limiting in any way.

In some embodiments, the second weights determination module 830 candetermine the second weights. In some embodiments, the second weightscan be determined based on severity or impact of the type of eventsassociated with the performance check. In some embodiments, theplurality of second weights can be severity weights each representing apredetermined degree of severity of a respective first performance checkor a respective second performance check. For example, a safety shutdown event (represented by a safety code) is more severe than a warningevent (represented by a warning code), and a health check alarm is moresevere than a health check alert. In some embodiments, the secondweights can be exponentially or linearly decaying weights based onexponential decay function or linear decay function. Example severityweighs are shown in table 1010 in FIG. 10. As shown in table 1010, eachseverity weight is a product of a weighting factor (e.g., 0.3, 0.1, 0.1,0.1, 0.2) and I_(max). For example, when I_(max)=10, the weight of thesafety codes is 3, the weight of the warning code codes is 1, the weightof the cycling code is 1, the weight of the health check alert is 1, andthe weight of the health check alarm is 2, in some embodiments. Whilethe embodiment of table 1010 uses five severity weights that cover codesor checks for safety codes, cycling code, warning codes, health checkalerts, and health check alarms, in other embodiments, each of thesecodes can be sort through and various weights can be assigned forindividual codes and checks, increasing the number of severity weightsoverall.

The following is an example of calculating an overall performance indexbased on the embodiments of performance checks illustrated in FIG. 11where time weighting (time varying weights) is not considered. Thisexample illustrates how the overall performance index can be calculatedfor a daily run. For example, if for the first 5-day window, the statuschecks have 1 safety code, 2 warning codes, and 0 cycling codesdetected, and the health checks have 1 health check alert and 0 alarmsdetected, then the overall performance index can be calculated as:

$\begin{matrix}{{{Performance}\mspace{14mu}{Index}\mspace{14mu}{for}\mspace{14mu}{window}\mspace{14mu} x} = {\max\left( {0,{{10} - \left\lbrack \left( {{\#\mspace{14mu}{of}\mspace{14mu}{safety}\mspace{14mu}{codes}*3} +} \right. \right.}} \right.}} \\{{\#\;\left( \mspace{11mu}{{of}\mspace{14mu}{warning}\mspace{14mu}{codes}*1} \right)} +} \\{\left( {\#\mspace{14mu}{of}\mspace{14mu}{cycling}\mspace{14mu}{codes}*1} \right) +} \\{\left( {\#\mspace{14mu}{of}\mspace{14mu}{health}\mspace{14mu}{check}\mspace{14mu}{alerts}*1} \right) +} \\\left. \left( {\#\mspace{14mu}{of}\mspace{14mu}{health}\mspace{14mu}{check}\mspace{14mu}{alarms}*2} \right) \right\rbrack \\{= {\max\left( {0,{{10} - \left\lbrack {\left( {1*3} \right) + \left( {2*1} \right) + \left( {0*1} \right) +} \right.}} \right.}} \\\left. \left. {\left( {1*1} \right) + \left( {0*2} \right)} \right\rbrack \right) \\{= {\max\left( {0,{{10} - \left\lbrack {3 + 2 + 0 + 1 + 0} \right\rbrack}} \right)}} \\{= {\max\left( {0,{{10} - 6}} \right)}} \\{= 4}\end{matrix}$

In the above example, the maximum value I_(max)=10, and the overallperformance index is constrained between 0 and I_(max), that is, between0 and 10 in this example. In some embodiments, the above calculation canbe repeated for each window through the data.

The following is an example of calculating an overall performance indexbased on the embodiments of performance checks illustrated in FIG. 12where time weighting (time varying weights) is considered. This exampleis described in relation to FIG. 14. Referring now to FIG. 14, anexample scenario 1400 of performance checks for generating an overallperformance index is shown, according to some embodiments. As shown inFIG. 14, performance checks are performed for the past 5 days. Forexample, health checks on “High Evap App” have detected 3 health checkalerts (1402, 1404, 1406) and 2 health check alarms (1408, 1410) in thepast 5 days. Health checks on “Low Cond. Ref Level” have detected 1health check alert (1420) occurred 72-96 hours ago. Similarly, statuschecks have detected 1 safety code (1430) on “Evap Low Pressure”occurred 96-120 hours ago, 1 cycling code (1450) on “Power Fault” 72-96hours ago, 1 waring code (1440) on “High Oil Temp” 24-48 hours ago, and2 waring codes (1460, 1462) on “Low Oil Pressure” 96-120 hours ago and48-72 hours ago.

In some embodiments, only the most recent instance of a performancecheck is considered in the calculation of the performance index. Forexample, as shown in FIG. 14, for the health checks on “High Evap App,”only the most recent instance (1410) is considered in the calculation ofthe performance index. Similarly, since there are 2 waring codes (1460,1462) on “Low Oil Pressure,” only the most recent instance (1462) isconsidered. As shown in FIG. 14, performance checks (1410, 1420, 1430,1440, 1450, and 1462) that are considered in the calculation of theperformance index are circled.

Continuing with the example in FIG. 14, in some embodiments, usingequation (1) as described above, the overall performance index can becalculated as:

$\begin{matrix}{{{Performance}\mspace{14mu}{Index}} = {\max\left( {0,{{10} - \left\lbrack {\left( {{sum}\mspace{20mu}{of}\mspace{14mu}{safety}\mspace{14mu}{codes}*W_{sc}} \right) +} \right.}} \right.}} \\{\left( {{sum}\mspace{20mu}{of}\mspace{14mu}{warning}\mspace{14mu}{codes}*W_{wc}} \right) +} \\{\left( {{sum}\mspace{20mu}{of}\mspace{14mu}{cycling}\mspace{14mu}{codes}*W_{cc}} \right) +} \\{\left( {{sum}\mspace{20mu}{of}\mspace{14mu}{health}\mspace{14mu}{check}\mspace{14mu}{alerts}*W_{h\; 1}} \right) +} \\{\left( {{sum}\mspace{20mu}{of}\mspace{14mu}{health}\mspace{14mu}{check}\mspace{14mu}{alarms}*W_{h\; 2}} \right)} \\{= {\max\left( {0,{{10} - \left\lbrack {\left( {0.14*3.0} \right) + \left( {\left( {{{0.6}06} + {{0.3}67}} \right)*10} \right) +} \right.}} \right.}} \\{\left( {0.22*1.0} \right) + \left( {0.22*1.0} \right) + \left( {1.0*2.0} \right)} \\{= {\max\left( {0,{{10} - \left\lbrack {383} \right\rbrack}} \right)}} \\{= 6.17}\end{matrix}$

As can be seen from the above example of FIG. 14, time weighting (timevarying weights) is considered in the performance checks. For example,the two warning codes 1440 and 1462 have values of 0.606 and 0.367,respectively, taking the time varying weights as described in relationto FIG. 12 into consideration. In the above example, the maximum valueI_(max)=10, and the overall performance index is constrained between 0and I_(max), that is, between 0 and 10 in this example. The I_(max) canhave other values. For example, if I_(max)=100, the overall performanceindex is constrained between 0 and 100.

The following is an implementation of the generation of the performanceindex in pseudocode, in some embodiments.

Read chiller time series data Read chiller codes: safety codes, warningcodes, cycling codes, and operating codes Define inclusion interval = 5days Define reporting frequency = 1 days Define weights = {‘SAF-CODE’ :3.0, ‘WAR-CODE’ : 1.0, ‘CYC-CODE’: 1.0, ‘health_check_alert’ : 1.0,‘health_check_alarm’ : 2.0} Define range of index = {‘min’ : 0, ‘max’ :10}Define parameters using as threshold values for health check rules:

param values = {′percent_fla_min′ : 10.0, ′cond_app_alert′ : 3.5,′cond_app_alarm′ : 5, ‘cond_app_runtime’ : 0.3, ′low_ref_level_alert′ :15, ′low_ref_level_alarm′ : 10, ‘ref_level_runtime’ : 0.5,′cond_entering_water_alarm′ : 85, ‘cond_entering_water_runtime’ : 0.05,′evap_app_alert′ : 3.5, ′evap_app_alarm′ : 5, ‘evap_app_runtime’ : 0.3,′high_oil_temp_alert′ : 155, ′high_oil_temp_alarm′ : 165,‘high_oil_temp_runtime’ : 0.05, ′high_ref_level_alarm′ : 90,′low_cond_water_entering_temp_alert′ : 49,′low_cond_water_entering_temp_alarm′ : 47, ′evap_delta_temp′ : 1.5}For each day in dataset, skipping by reporting frequency:

Look at window of (current date - inclusion interval) to current date;Identify any safety codes, warning codes, and cycle codes occurring inthis window; Run health checks for all points in window (remove pointswhen chiller wasn't running); Aggregate any violations of health checksand codes to produce index.

In some embodiments, the time varying performance indication system 502can be configured to determine that a total runtime of the connectequipment in a past time window, and generate the overall performanceindex only when the total runtime of the connect equipment in the pasttime window satisfies a predetermine threshold. For example, theperformance index may be calculated only for connected equipment that isconsidered to be running for more than a predetermined total runtime orthreshold (e.g., 2 hours) in a time window (e.g., last 24-hour period).In some embodiments, if a chiller (or other connected equipment) is notconsidered to be running, the performance index may not show up in aheat map or metrics, but may be listed in a grey section that containsall chillers that are either not running or that have been flagged ormarked as disregard. In some embodiments, the motor full-load amps (MOTFLA) point is being used to calculate whether or not a chiller isrunning for a health check. In other embodiments, a method that utilizesoperational codes and potentially input power (INPUT KW) may be used.

In some embodiments, health checks can consider a predetermined rollingwindow (e.g., 30-day rolling window) for their frequency indexcalculations (time in alert or alarm divided by total runtime hours). Insome embodiments, for the performance index, a different predeterminedrolling window (e.g., 24-hour rolling window) may be used, but it mayfollow the same logic as far as putting in Alert or Alarm stage if thefrequency index value is above 20%. In some embodiments, an examplehealth check frequency index can be calculated as:

${{Health}\mspace{14mu}{Check}\mspace{14mu}{Frequency}\mspace{14mu}{Index}} = \frac{{Time}\mspace{14mu}{in}\mspace{14mu}{Alert}\mspace{14mu}{or}\mspace{14mu}{Alarm}\mspace{14mu}{in}\mspace{14mu}{Past}\mspace{14mu} 30\mspace{14mu}{Days}}{{Total}\mspace{14mu}{Runtime}\mspace{14mu}{in}\mspace{14mu}{Past}\mspace{14mu} 30\mspace{14mu}{Days}}$

In some embodiments, an example performance frequency index can becalculated as:

${{Performance}\mspace{14mu}{Frequency}\mspace{14mu}{Index}} = \frac{{Time}\mspace{14mu}{in}\mspace{14mu}{Alert}\mspace{14mu}{or}\mspace{14mu}{Alarm}\mspace{14mu}{in}\mspace{14mu}{Past}\mspace{14mu} 24\mspace{14mu}{Hours}}{{Total}\mspace{14mu}{Runtime}\mspace{14mu}{in}\mspace{14mu}{Past}\mspace{14mu} 24\mspace{14mu}{Hours}}$

It should be understood that the example health check frequency indexand the example performance frequency index are provided forillustrative purposes only and should not be regarded as limiting in anyway. In some embodiments, the health check frequency index and/or theperformance frequency index can be updated periodically (e.g., every 4hours).

In some embodiments, the generated performance index can be rated and/orcolor coded to indicate if the overall health of the connected equipmentshould be concerned and further investigation should be conducted. Forexample, the following example threshold table, Table 4, can be usedwhen the I_(max)=100.

TABLE 4 threshold table for index values Index Value Range Rating Color75.0-100.0 Acceptable Green 50.0-75.0  Alert Yellow 0.0-50.0 Alarm Red

In some embodiments, the time varying performance indication system 502can cause an adjustment to the connect equipment based on the overallperformance index generated for the connected equipment. For example, insome embodiments, a report can be generated to indicate the overallhealth of the connected equipment. The report can be transmitted via thenetwork 446 to another system or device to prompt further investigationof the connected equipment. One or more adjustments or actions may beperformed based on the further investigation as a result of the value ofoverall performance index.

Referring now to FIG. 15, an example user interface 1500 showing anexample of the calculated performance index over time is shown,according to some embodiments. In some embodiments, the user interface1500 can allow a user to hover over points and see any failed statuschecks and health checks that occurred during those times. In someembodiments, the user interface may also allow for the customization andtuning of parameters used in the algorithm, including how often theindex is calculated, the date range to include, and weights forindividual performance checks. In some embodiments, the user interfacemay provide an option to weigh the impact of failed performance checksby when they occurred. Such time weighting is beneficial because whileusers consider what has happened in the recent past, they may also wantthe index to be responsive to maintenance actions or other suddenchanges in condition. In some embodiments, using exponentially orlinearly decaying weights can enable the inclusion window adapt quicklyto positive and negative changes in the index.

Referring now to FIG. 16, a flow diagram illustrating a process 1600 ofgenerating a performance index for connected equipment is shown,according to some embodiments. The process 1600 can be performed by thetime varying performance indication system 502 to automaticallygenerating a performance index for connected equipment. For example, theprocessor 814 of the processing circuit 812 can be configured to performthe process 1600. The process can include obtaining data points of aplurality of monitored variables and a plurality of status codes frompast N time units (Stage 1602). N is a number, such as an integer. Theplurality of monitored variables are measured by connected equipment,and the plurality of status codes are generated by the connectedequipment. In some embodiments, the time units can be days, hours,minutes, seconds, weeks, months, or years. The process can includeobtaining a plurality of connected equipment specific parameters thatare parameters specific to the connected equipment (Stage 1604). Theprocess can include performing a plurality of first performance checksfor the connected equipment using the plurality of status codes from thepast N time units (Stage 1606). The process can include performing aplurality of second performance checks for the connected equipment usingthe data points of the plurality of monitored variables from the past Ntime units, the plurality of connected equipment specific parameters,and a plurality of predetermined rules (Stage 1608). The process caninclude determining a plurality of individual performance checkindicators based on the first performance checks and the secondperformance checks using a plurality of first weights each determinedbased on a different timing (Stage 1610). The process can includegenerating an overall performance index for the connected equipmentusing the plurality of individual performance check indicators and aplurality of second weights (Stage 1612). The process can includecausing an adjustment to the connect equipment based on the overallperformance index generated for the connected equipment (Stage 1614).

Systems and methods described herein can aggregate a plurality ofperformance checks and generate an overall performance index as a metricfor the overall health of a chiller or other connected equipment thatcan be tracked over time. By combining the health checks, cycling,warning, and safety codes, an aggregate health index for a chiller orother connected equipment can be calculated. This index can indicate theoverall health of the connected equipment at a given time and providefield technicians and diagnostic engineers the ability to pinpoint whichconnected equipment is most critical to attend to. Tracking thisperformance index over time can draw attention to connected equipmentthat are consistently in poor health or that are trending in a negativedirection, prompting branch service technicians to investigate.Connected equipment performance indices could also be aggregated acrossdifferent machines to obtain an overall picture of the health of aspecific customer's connected equipment or of the connected equipmentserviced by a specific branch or region, providing better diagnosisabilities and results.

Configuration of Exemplary Embodiments

The construction and arrangement of the systems and methods as shown inthe various exemplary embodiments are illustrative only. Although only afew embodiments have been described in detail in this disclosure, manymodifications are possible (e.g., variations in sizes, dimensions,structures, shapes and proportions of the various elements, values ofparameters, mounting arrangements, use of materials, colors,orientations, etc.). For example, the position of elements can bereversed or otherwise varied and the nature or number of discreteelements or positions can be altered or varied. Accordingly, all suchmodifications are intended to be included within the scope of thepresent disclosure. The order or sequence of any process or method stepscan be varied or re-sequenced according to alternative embodiments.Other substitutions, modifications, changes, and omissions can be madein the design, operating conditions and arrangement of the exemplaryembodiments without departing from the scope of the present disclosure.

The present disclosure contemplates methods, systems and programproducts on any machine-readable media for accomplishing variousoperations. The embodiments of the present disclosure can be implementedusing existing computer processors, or by a special purpose computerprocessor for an appropriate system, incorporated for this or anotherpurpose, or by a hardwired system. Embodiments within the scope of thepresent disclosure include program products comprising machine-readablemedia for carrying or having machine-executable instructions or datastructures stored thereon. Such machine-readable media can be anyavailable media that can be accessed by a general purpose or specialpurpose computer or other machine with a processor. By way of example,such machine-readable media can comprise RAM, ROM, EPROM, EEPROM, CD-ROMor other optical disk storage, magnetic disk storage or other magneticstorage devices, or any other medium which can be used to carry or storedesired program code in the form of machine-executable instructions ordata structures and which can be accessed by a general purpose orspecial purpose computer or other machine with a processor. Combinationsof the above are also included within the scope of machine-readablemedia. Machine-executable instructions include, for example,instructions and data which cause a general purpose computer, specialpurpose computer, or special purpose processing machines to perform acertain function or group of functions.

Although the figures show a specific order of method steps, the order ofthe steps may differ from what is depicted. Also two or more steps canbe performed concurrently or with partial concurrence. Such variationwill depend on the software and hardware systems chosen and on designerchoice. All such variations are within the scope of the disclosure.Likewise, software implementations could be accomplished with standardprogramming techniques with rule based logic and other logic toaccomplish the various connection steps, processing steps, comparisonsteps and decision steps.

1. A system comprising: equipment configured to measure a plurality ofmonitored variables and generate a plurality of status codes; andcircuitry configured to: perform a plurality of performance checks forthe equipment using data points of the plurality of monitored variables,the plurality of status codes, and the plurality of equipment specificparameters; determine a plurality of individual performance checkindicators based on the plurality of performance checks using aplurality of first weights determined based on different timings; andgenerate an overall performance index for the connected equipment usingthe plurality of individual performance check indicators and a pluralityof second weights.
 2. The system of claim 1, wherein the equipment is achiller.
 3. The system of claim 1, wherein the plurality of performancechecks comprise applying the data points of the plurality of monitoredvariables and the plurality of connected equipment specific parametersto a plurality of predetermined rules.
 4. The system of claim 1, whereinthe second weights are determined based on a predetermined degree ofseverity of a respective performance check of the plurality ofperformance checks.
 5. The system of claim 1, wherein the circuitry isfurther configured to: determine a total runtime of the equipment in apast time window; and generate the overall performance index only whenthe total runtime of the equipment in the past time window satisfies acriterion.
 6. The system of claim 1, wherein the circuitry is furtherconfigured to cause an adjustment to the equipment based on the overallperformance index.
 7. The system of claim 1, wherein the plurality ofperformance checks comprise first performance checks that use theplurality of status codes and second performance checks that use theplurality of monitored variables and the plurality of equipment-specificparameters.
 8. The system of claim 1, wherein the plurality ofperformance checks comprise status checks and health checks.
 9. A methodcomprising: obtaining data points of a monitored variable measured byequipment, status codes generated by the equipment, and parametersspecific to the equipment; performing a plurality of performance checksfor the equipment using the data points of the monitored variable, thestatus codes, and the parameters; determining a plurality of individualperformance check indicators based on the performance checks using aplurality of first weights determined based on different timings; anddetermining, an overall performance index for the equipment using theplurality of individual performance check indicators and a plurality ofsecond weights.
 10. The method of claim 9, wherein the equipmentcomprises a chiller.
 11. The method of claim 9, wherein the plurality ofperformance checks comprise applying the data points of monitoredvariable and the parameters to a predetermined rule.
 12. The method ofclaim 9, wherein the plurality of second weights is determined based ona degree of severity of a respective performance check of the pluralityof performance checks.
 13. The method of claim 9, further comprising:determining a total runtime of the equipment in a past time window; andgenerating the overall performance index only when the total runtimesatisfies a criterion.
 14. The method of claim 9, further comprising:causing an adjustment to the equipment based on the overall performanceindex.
 15. The method of claim 9, wherein performing the plurality ofperformance checks comprises performing a first performance check usingthe plurality of status codes and performing a second performance checkusing the plurality of monitored variables and the plurality ofequipment-specific parameters.
 16. The method of claim 9, wherein theperformance checks comprise status checks and health checks.
 17. Anon-transitory computer-readable medium having computer-executableinstructions stored therein, the instructions when executed by at leastone processor, causing the at least one processor to perform operationscomprising: obtaining data points of a variable measured by equipmentand status codes for the equipment; obtaining a parameter specific tothe equipment; performing a plurality of performance checks using thedata points, the parameter, and the status codes; determining aplurality of individual performance check indicators plurality ofperformance checks and a plurality of first weights determined based ondifferent timings; and generating an overall performance index using theplurality of individual performance check indicators and a secondweight.
 18. The non-transitory computer-readable medium of claim 17,wherein the plurality of performance checks comprise applying the datapoints and the parameter to a predetermined rule.
 19. The non-transitorycomputer-readable medium of claim 17, wherein the second weight isdetermined based on a degree of severity of a respective performancecheck of the plurality of performance checks.
 20. The non-transitorycomputer-readable medium of claim 17, wherein the instructions whenexecuted by the at least one processor, cause the at least one processorto perform operations further comprising: causing an adjustment to theequipment based on the overall performance index.